<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_View
 * @subpackage Helper
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @version    $Id: HeadLink.php 16971 2009-07-22 18:05:45Z mikaelkael $
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/** Zend_View_Helper_Placeholder_Container_Standalone */
require_once 'Zend/View/Helper/Placeholder/Container/Standalone.php';

/**
 * Zend_Layout_View_Helper_HeadLink
 *
 * @see        http://www.w3.org/TR/xhtml1/dtds.html
 * @uses       Zend_View_Helper_Placeholder_Container_Standalone
 * @package    Zend_View
 * @subpackage Helper
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_View_Helper_HeadLink extends Zend_View_Helper_Placeholder_Container_Standalone
{
	/**
	 * $_validAttributes
	 *
	 * @var array
	 */
	protected $_itemKeys = array('charset', 'href', 'hreflang', 'media', 'rel', 'rev', 'type', 'title', 'extras');

	/**
	 * @var string registry key
	 */
	protected $_regKey = 'Zend_View_Helper_HeadLink';

	/**
	 * Constructor
	 *
	 * Use PHP_EOL as separator
	 *
	 * @return void
	 */
	public function __construct()
	{
		parent::__construct();
		$this->setSeparator(PHP_EOL);
	}

	/**
	 * headLink() - View Helper Method
	 *
	 * Returns current object instance. Optionally, allows passing array of
	 * values to build link.
	 *
	 * @return Zend_View_Helper_HeadLink
	 */
	public function headLink(array $attributes = null, $placement = Zend_View_Helper_Placeholder_Container_Abstract::APPEND)
	{
		if (null !== $attributes) {
			$item = $this->createData($attributes);
			switch ($placement) {
				case Zend_View_Helper_Placeholder_Container_Abstract::SET:
					$this->set($item);
					break;
				case Zend_View_Helper_Placeholder_Container_Abstract::PREPEND:
					$this->prepend($item);
					break;
				case Zend_View_Helper_Placeholder_Container_Abstract::APPEND:
				default:
					$this->append($item);
					break;
			}
		}
		return $this;
	}

	/**
	 * Overload method access
	 *
	 * Creates the following virtual methods:
	 * - appendStylesheet($href, $media, $conditionalStylesheet, $extras)
	 * - offsetSetStylesheet($index, $href, $media, $conditionalStylesheet, $extras)
	 * - prependStylesheet($href, $media, $conditionalStylesheet, $extras)
	 * - setStylesheet($href, $media, $conditionalStylesheet, $extras)
	 * - appendAlternate($href, $type, $title, $extras)
	 * - offsetSetAlternate($index, $href, $type, $title, $extras)
	 * - prependAlternate($href, $type, $title, $extras)
	 * - setAlternate($href, $type, $title, $extras)
	 *
	 * Items that may be added in the future:
	 * - Navigation?  need to find docs on this
	 *   - public function appendStart()
	 *   - public function appendContents()
	 *   - public function appendPrev()
	 *   - public function appendNext()
	 *   - public function appendIndex()
	 *   - public function appendEnd()
	 *   - public function appendGlossary()
	 *   - public function appendAppendix()
	 *   - public function appendHelp()
	 *   - public function appendBookmark()
	 * - Other?
	 *   - public function appendCopyright()
	 *   - public function appendChapter()
	 *   - public function appendSection()
	 *   - public function appendSubsection()
	 *
	 * @param mixed $method
	 * @param mixed $args
	 * @return void
	 */
	public function __call($method, $args)
	{
		if (preg_match('/^(?P<action>set|(ap|pre)pend|offsetSet)(?P<type>Stylesheet|Alternate)$/', $method, $matches)) {
			$argc   = count($args);
			$action = $matches['action'];
			$type   = $matches['type'];
			$index  = null;

			if ('offsetSet' == $action) {
				if (0 < $argc) {
					$index = array_shift($args);
					--$argc;
				}
			}

			if (1 > $argc) {
				require_once 'Zend/View/Exception.php';
				throw new Zend_View_Exception(sprintf('%s requires at least one argument', $method));
			}

			if (is_array($args[0])) {
				$item = $this->createData($args[0]);
			} else {
				$dataMethod = 'createData' . $type;
				$item       = $this->$dataMethod($args);
			}

			if ($item) {
				if ('offsetSet' == $action) {
					$this->offsetSet($index, $item);
				} else {
					$this->$action($item);
				}
			}

			return $this;
		}

		return parent::__call($method, $args);
	}

	/**
	 * Check if value is valid
	 *
	 * @param  mixed $value
	 * @return boolean
	 */
	protected function _isValid($value)
	{
		if (!$value instanceof stdClass) {
			return false;
		}

		$vars         = get_object_vars($value);
		$keys         = array_keys($vars);
		$intersection = array_intersect($this->_itemKeys, $keys);
		if (empty($intersection)) {
			return false;
		}

		return true;
	}

	/**
	 * append()
	 *
	 * @param  array $value
	 * @return void
	 */
	public function append($value)
	{
		if (!$this->_isValid($value)) {
			require_once 'Zend/View/Exception.php';
			throw new Zend_View_Exception('append() expects a data token; please use one of the custom append*() methods');
		}

		return $this->getContainer()->append($value);
	}

	/**
	 * offsetSet()
	 *
	 * @param  string|int $index
	 * @param  array $value
	 * @return void
	 */
	public function offsetSet($index, $value)
	{
		if (!$this->_isValid($value)) {
			require_once 'Zend/View/Exception.php';
			throw new Zend_View_Exception('offsetSet() expects a data token; please use one of the custom offsetSet*() methods');
		}

		return $this->getContainer()->offsetSet($index, $value);
	}

	/**
	 * prepend()
	 *
	 * @param  array $value
	 * @return Zend_Layout_ViewHelper_HeadLink
	 */
	public function prepend($value)
	{
		if (!$this->_isValid($value)) {
			require_once 'Zend/View/Exception.php';
			throw new Zend_View_Exception('prepend() expects a data token; please use one of the custom prepend*() methods');
		}

		return $this->getContainer()->prepend($value);
	}

	/**
	 * set()
	 *
	 * @param  array $value
	 * @return Zend_Layout_ViewHelper_HeadLink
	 */
	public function set($value)
	{
		if (!$this->_isValid($value)) {
			require_once 'Zend/View/Exception.php';
			throw new Zend_View_Exception('set() expects a data token; please use one of the custom set*() methods');
		}

		return $this->getContainer()->set($value);
	}


	/**
	 * Create HTML link element from data item
	 *
	 * @param  stdClass $item
	 * @return string
	 */
	public function itemToString(stdClass $item)
	{
		$attributes = (array) $item;
		$link       = '<link ';

		foreach ($this->_itemKeys as $itemKey) {
			if (isset($attributes[$itemKey])) {
				if(is_array($attributes[$itemKey])) {
					foreach($attributes[$itemKey] as $key => $value) {
						$link .= sprintf('%s="%s" ', $key, ($this->_autoEscape) ? $this->_escape($value) : $value);
					}
				} else {
					$link .= sprintf('%s="%s" ', $itemKey, ($this->_autoEscape) ? $this->_escape($attributes[$itemKey]) : $attributes[$itemKey]);
				}
			}
		}

		if ($this->view instanceof Zend_View_Abstract) {
			$link .= ($this->view->doctype()->isXhtml()) ? '/>' : '>';
		} else {
			$link .= '/>';
		}

		if (($link == '<link />') || ($link == '<link >')) {
			return '';
		}

		if (isset($attributes['conditionalStylesheet'])
		&& !empty($attributes['conditionalStylesheet'])
		&& is_string($attributes['conditionalStylesheet']))
		{
			$link = '<!--[if ' . $attributes['conditionalStylesheet'] . ']> ' . $link . '<![endif]-->';
		}

		return $link;
	}

	/**
	 * Render link elements as string
	 *
	 * @param  string|int $indent
	 * @return string
	 */
	public function toString($indent = null)
	{
		$indent = (null !== $indent)
		? $this->getWhitespace($indent)
		: $this->getIndent();

		$items = array();
		$this->getContainer()->ksort();
		foreach ($this as $item) {
			$items[] = $this->itemToString($item);
		}

		return $indent . implode($this->_escape($this->getSeparator()) . $indent, $items);
	}

	/**
	 * Create data item for stack
	 *
	 * @param  array $attributes
	 * @return stdClass
	 */
	public function createData(array $attributes)
	{
		$data = (object) $attributes;
		return $data;
	}

	/**
	 * Create item for stylesheet link item
	 *
	 * @param  array $args
	 * @return stdClass|false Returns fals if stylesheet is a duplicate
	 */
	public function createDataStylesheet(array $args)
	{
		$rel                   = 'stylesheet';
		$type                  = 'text/css';
		$media                 = 'screen';
		$conditionalStylesheet = false;
		$href                  = array_shift($args);

		if ($this->_isDuplicateStylesheet($href)) {
			return false;
		}

		if (0 < count($args)) {
			$media = array_shift($args);
			if(is_array($media)) {
				$media = implode(',', $media);
			} else {
				$media = (string) $media;
			}
		}
		if (0 < count($args)) {
			$conditionalStylesheet = array_shift($args);
			if(!empty($conditionalStylesheet) && is_string($conditionalStylesheet)) {
				$conditionalStylesheet = (string) $conditionalStylesheet;
			} else {
				$conditionalStylesheet = null;
			}
		}

		if(0 < count($args) && is_array($args[0])) {
			$extras = array_shift($args);
			$extras = (array) $extras;
		}

		$attributes = compact('rel', 'type', 'href', 'media', 'conditionalStylesheet', 'extras');
		return $this->createData($attributes);
	}

	/**
	 * Is the linked stylesheet a duplicate?
	 *
	 * @param  string $uri
	 * @return bool
	 */
	protected function _isDuplicateStylesheet($uri)
	{
		foreach ($this->getContainer() as $item) {
			if (($item->rel == 'stylesheet') && ($item->href == $uri)) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Create item for alternate link item
	 *
	 * @param  array $args
	 * @return stdClass
	 */
	public function createDataAlternate(array $args)
	{
		if (3 > count($args)) {
			require_once 'Zend/View/Exception.php';
			throw new Zend_View_Exception(sprintf('Alternate tags require 3 arguments; %s provided', count($args)));
		}

		$rel   = 'alternate';
		$href  = array_shift($args);
		$type  = array_shift($args);
		$title = array_shift($args);

		if(0 < count($args) && is_array($args[0])) {
			$extras = array_shift($args);
			$extras = (array) $extras;

			if(isset($extras['media']) && is_array($extras['media'])) {
				$extras['media'] = implode(',', $extras['media']);
			}
		}

		$href  = (string) $href;
		$type  = (string) $type;
		$title = (string) $title;

		$attributes = compact('rel', 'href', 'type', 'title', 'extras');
		return $this->createData($attributes);
	}
}
